How can a fungicide application translate into better plant health — aside from reducing the impact from a given disease or helping the plant avoid the disease altogether? Here’s an explanation from BASF’s Vince Ulstad, using Headline as an example.

In sunflower, Headline is labeled for the control of rust, white rust, septoria leafspot, alternaria leafspot, downy mildew and powdery mildew. Along with protection against those diseases, the fungicide also, Ulstad says, helps the plant deal with various environmental stresses like frost, hail or drought that may afflict it during the growing season. The key is for the plant to be protected prior to the onset of such stresses — along the same lines of a human getting a flu shot.

What’s occurring in the physiological sense? The same mode of action that Headline uses to kill a fungus also works on green plant cells, Ulstad explains. The difference is that whereas green cells get their energy from sunlight-induced chlorophyll, a fungus derives all of its energy from respiration.

In the absence of sunlight, green cells also undergo respiration. As they respire during nighttime hours, energy is produced, carbon is released — “and there is a redirection of energy flow within the cell.”

That’s where Headline comes into play. It suppresses the amount of nighttime respiration occurring within green plant cells — and that energy is then funneled into other physiological and biochemical pathways. Among the most important is a smoother transition in the plant’s ability to convert nitrate-nitrogen for its use.

“Other pathways influenced by the redirection of energy flow result in measurable increases of various natural plant enzymes that help green plants mediate environmental stress,” Ulstad adds. As green plants better handle various stresses, the plants feel less need to speed up the maturing process. The eventual result is an overall healthier plant.